// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/run_loop.h"

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/location.h"
#include "base/macros.h"
#include "base/message_loop/message_loop.h"
#include "base/single_thread_task_runner.h"
#include "base/threading/thread_task_runner_handle.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace base {

namespace {

    void QuitWhenIdleTask(RunLoop* run_loop, int* counter)
    {
        run_loop->QuitWhenIdle();
        ++(*counter);
    }

    void ShouldRunTask(int* counter)
    {
        ++(*counter);
    }

    void ShouldNotRunTask()
    {
        ADD_FAILURE() << "Ran a task that shouldn't run.";
    }

    void RunNestedLoopTask(int* counter)
    {
        RunLoop nested_run_loop;

        // This task should quit |nested_run_loop| but not the main RunLoop.
        ThreadTaskRunnerHandle::Get()->PostTask(
            FROM_HERE, Bind(&QuitWhenIdleTask, Unretained(&nested_run_loop), Unretained(counter)));

        ThreadTaskRunnerHandle::Get()->PostDelayedTask(
            FROM_HERE, Bind(&ShouldNotRunTask), TimeDelta::FromDays(1));

        MessageLoop::ScopedNestableTaskAllower allower(MessageLoop::current());
        nested_run_loop.Run();

        ++(*counter);
    }

    class RunLoopTest : public testing::Test {
    protected:
        RunLoopTest() = default;

        MessageLoop message_loop_;
        RunLoop run_loop_;
        int counter_ = 0;

    private:
        DISALLOW_COPY_AND_ASSIGN(RunLoopTest);
    };

} // namespace

TEST_F(RunLoopTest, QuitWhenIdle)
{
    message_loop_.task_runner()->PostTask(
        FROM_HERE,
        Bind(&QuitWhenIdleTask, Unretained(&run_loop_), Unretained(&counter_)));
    message_loop_.task_runner()->PostTask(
        FROM_HERE, Bind(&ShouldRunTask, Unretained(&counter_)));
    message_loop_.task_runner()->PostDelayedTask(
        FROM_HERE, Bind(&ShouldNotRunTask), TimeDelta::FromDays(1));

    run_loop_.Run();
    EXPECT_EQ(2, counter_);
}

TEST_F(RunLoopTest, QuitWhenIdleNestedLoop)
{
    message_loop_.task_runner()->PostTask(
        FROM_HERE, Bind(&RunNestedLoopTask, Unretained(&counter_)));
    message_loop_.task_runner()->PostTask(
        FROM_HERE,
        Bind(&QuitWhenIdleTask, Unretained(&run_loop_), Unretained(&counter_)));
    message_loop_.task_runner()->PostTask(
        FROM_HERE, Bind(&ShouldRunTask, Unretained(&counter_)));
    message_loop_.task_runner()->PostDelayedTask(
        FROM_HERE, Bind(&ShouldNotRunTask), TimeDelta::FromDays(1));

    run_loop_.Run();
    EXPECT_EQ(4, counter_);
}

TEST_F(RunLoopTest, QuitWhenIdleClosure)
{
    message_loop_.task_runner()->PostTask(FROM_HERE,
        run_loop_.QuitWhenIdleClosure());
    message_loop_.task_runner()->PostTask(
        FROM_HERE, Bind(&ShouldRunTask, Unretained(&counter_)));
    message_loop_.task_runner()->PostDelayedTask(
        FROM_HERE, Bind(&ShouldNotRunTask), TimeDelta::FromDays(1));

    run_loop_.Run();
    EXPECT_EQ(1, counter_);
}

// Verify that the QuitWhenIdleClosure() can run after the RunLoop has been
// deleted. It should have no effect.
TEST_F(RunLoopTest, QuitWhenIdleClosureAfterRunLoopScope)
{
    Closure quit_when_idle_closure;
    {
        RunLoop run_loop;
        quit_when_idle_closure = run_loop.QuitWhenIdleClosure();
        run_loop.RunUntilIdle();
    }
    quit_when_idle_closure.Run();
}

} // namespace base
